In recent years, there have been reports that domain wall shifts by current were observed in magnetic nanowires with submicron widths. Magnetic memories that can cause domain walls to shift by taking advantage of the reported effect have been suggested. In such a magnetic memory, a magnetic nanowire divided into plural magnetic domains is used, and information (data) “0” or “1” is associated with the magnetization directions of the magnetic domains. In this manner, information is stored. When a current is flowed, the domain walls shift, and accordingly, the magnetic domains shift. As a result, the information (data) stored in the magnetic domains also shifts, and can be read by a sensor and be written by a write unit. That is, the magnetic domains are equivalent to memory cells. In general, there is an increasing demand for magnetic memories that have larger capacities through increases in cell density or the like, and consume less power.
In a magnetic memory of the above described domain wall shifting type, a pinning site for pinning the domain walls is necessary to prevent changes in the locations of the domain walls due to external disturbance such as heat. As a specific example, a method of forming a physical notch in a magnetic nanowire has been suggested. Also, a method of forming a domain wall pinning site by ion beam irradiation has been suggested.